201203594 六、發明說明： 【發明所屬之技術領域】 本發明係關於交指式背接點光伏打電池之製造方法。 【先前技術】 交指式背接點（IBC )電池為在電池之後側具有發射極 接點及基極接點兩者之光伏打電池’發射極接點及基極接 點為交指式’用於電子與電洞之分開的收集。消除前側接 點避免了對在遮光損失與串聯電阻之間進行折衷之需要。 IBC電池之製造製程常需要若干遮蔽步驟及對準步驟，因為 在電池之後側’存在對分離發射極區域與基極區域及分離 且適當地對準發射極接點與基極接點之需要。 已提議用於減少用於製造IBC電池之製程序列之複雜 性的方法。舉例而言’在「Realizati〇n 0f self_aligned back contact cells」（Electrochemical and So]id-State Letters, 11 (5)，H114-H117，2008)中，P. Papet 等人描述一製程序列， 其中僅使用一個微影步驟且其中隨後不需要對準步驟。發 射極接點與基極接點之間的分離係藉由使用金屬遮罩在石夕 基板中化學蝕刻凹槽而獲得，其中遮罩之底蝕導致形成懸 臂’懸臂足夠大（數微米）以避免在金屬沈積後的兩個接 點類型之間的短路。201203594 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a method of manufacturing an interdigitated back contact photovoltaic cell. [Prior Art] The interdigitated back contact (IBC) battery is a photovoltaic cell with an emitter contact and a base contact on the back side of the battery. The emitter contact and the base contact are interdigitated. Used for separate collection of electrons and holes. Eliminating the front side contacts eliminates the need to compromise between shading losses and series resistance. The IBC battery manufacturing process often requires a number of masking steps and alignment steps because there is a need to separate the emitter and base regions and separate and properly align the emitter and base contacts on the back side of the cell. A method has been proposed for reducing the complexity of the program for manufacturing IBC batteries. For example, in "Realizati〇n 0f self_aligned back contact cells" (Electrochemical and So) id-State Letters, 11 (5), H114-H117, 2008), P. Papet et al. describe a program sequence in which only A lithography step is used and there is no need for an alignment step subsequently. The separation between the emitter contact and the base contact is obtained by chemically etching the recess in the Shih-Tsin substrate using a metal mask, wherein the undercut of the mask results in the formation of a cantilever 'cantilever sufficiently large (several microns) Avoid short circuits between the two contact types after metal deposition.
在「Super self-aligned technology for backside contact solar cells: a route to low cost and high efficiency」（IEEE PVSC 2009 )中，P. Verlinden等人提議一種用於製造背面 接點光伏打電池之方法，該方法僅需要一個光微影步驟， 4 201203594 準在電池之後側處的n+摻雜區域與p +摻雜區域之 隹係氪由使用氧化物遮罩在矽基板中化學蝕刻凹槽 且底餘該遮罩使得氧化物懸臂形成於凹槽之側面來獲得。 凹槽之底部與側壁經熱氧化以提供-鈍化層，及將一氮化 。積$、氧化物層之上。接下來’使用各向異性反應性 離子餘刻，且蚀田助i辟& 慜I作為遮罩，在凹槽之底部處氧 ::及氣化物層中打開…。氧切層及，切層2 :中：：之側壁處。接著執行蝴預沈積，且在單-高溫步 :中：散兩個推雜區域（n+發射極區域及基極中之二 扩為了提供n+摻雜區域與p+播雜區域之間的分離，將 二：槽之側壁處的氧切/氮切堆疊用作遮蔽層。為 射極接點及基極接點，藉由真空蒸鐘沈積A1層(該 致:心以非常差的步階覆蓋為特徵)，使得懸臂之存在導 致兔射極接點與基極接點之間的分離。 在導 【發明内容】 本發明之具體實例之_ 部具有兩種接„之太^ φ ^供—種用於製造在後 、植接點之太險能電池之良好方法。 以上目標藉由根據本發 本發明之具體實例：=:方法實現。 光伏打電池之方法，其中避免了對=造交指式背接點 準步驟之需要，且其中愈先前步驟之需要及對尉 步驟之數目。在根據—具體實例少了製程 用於分离“型摻雜區域與？型：中，避免了對提供 將在於石夕基板中触刻之凹槽之側面：或之遮蔽層之需要。 J面棱供懸臂或懸垂部分與 201203594 定向摻雜之組合用於η型摻雜區域與p型摻雜區域之間的 分離。可在單-步驟中執行用於形成發射極、背表面場及 前表面場的摻雜劑之擴散。此外，懸臂亦可用於發射極接 點與基極接點之間的分㉟，使得單一金屬化步驟可形 成兩個接點類型。 在-第-具體實例中，本發明係關於一種用於製造交 指式背接點光伏打電池之方法，該方法包含：在—半導體 (例如’矽）基板之一後表面上裎 衣®上钕供一包含一第一摻雜劑 類型之第一摻雜層；提供一上覆 復忒第一摻雜層之介電遮蔽 層；形成穿過該介電遮蔽層及該第一 %乐 穋雜層之複數個凹 槽’該複數個凹槽在與該後表面實皙 員買上正父（例如，正交） 之一方向上延伸至該石夕内且在兮诘 且在^數個凹槽之#丨面在該第 払雜層下方在一側向方向上延伸 ^ τ，在與该後表面實質上 正父（例如，正交）之一方向上執 ^ L ^ 钒仃一疋向摻雜步驟，藉 此在該複數個凹槽之一底部提供 、'^第一摻雜劑類型不同 的一第二榜雜劑類型之#雜劑；勃并 4Δ Α. 仃—摻雜劑擴散步驟， 藉此在遠基板之該後側處形成處於該複數個凹槽之間的一 第：類型之摻雜區域及在該複數個凹槽之該底部處的一第 一類型之摻雜區域。在本發明之上 @ . ^ ^ 下文中，「與後表面實 夤上正交」思谓自後表面之正交方 地不大於10。。 Θ偏離不大於3。。’較佳 本發明之具體實例之一優勢為 . ^ _ ,.s ΛΙ 弟類型之摻雜區域盥 第一類型之摻雜區域「自對準」， ^ ^ m P ,不需要提供用於 將第一類型之摻雜區域與第二類 t雜區域分離的專用 6 201203594 遮罩或遮蔽層。 本i明之具體實例之—優勢為同時產生 射極。此提供處理太陽能電池之簡化方式。表面场及發 在本發明之具體實例中，基板可（例 第一摻雜劑類型可為n型，a # 与η型基板’ 在此具體實例巾，換雜劑擴捧雜劑類型可為… 槽之間的η型區域（例如，皆本 3形成在複數個凹 槽之底部處的Ρ型區域（例如，發射極區域）。凹 或者’在本發明之具轉杳 型基板’第一摻雜劑類型可為例如)·為η 為"。在此具體實例中’捧雜劑擴散步驟; ::槽之間的ρ型區域（例如，發射極區域)及在複 或者，在本發明之具體=面場區域）。 型基板’第-摻雜劑類型可為：了(例如）為ρ 為η型。在此具體實例 1第二㈣劑類型可 複數個凹槽之間的Ρ型區㈣步驟可包含形成在 複數個喻轉…及在 或者，在本發明之具體實&射極區域）。 型基板，第-摻雜劑類型可為’基板可（例如）為P 為ρ型。在此具體實例中，#^ =二換雜劑類型可 複數個凹槽之間的n型巴域:雜劑擴散步驟可包含形成在 數個凹槽之底…… 發射極區域）及在複 :二處的p型區域（例如，背表面場區域）。 以層可（例如）為穆雜氧化物層或㈣非晶半 201203594 導體層（例如，非晶矽層）。 介電遮蔽層可為單-層或層之堆疊。介電遮蔽層可包 括任-合適的介電層，諸如，氧化物層及/或氮化物層。 形成該複數個凹槽可（例如）藉由f射㈣ 用於底触介電遮蔽層及第—推雜層之濕式餘刻來進行，濕 式触刻步驟導致凹槽在第—摻雜層下方在側向方向上（= 即’貫質上平行於後表面之方向）的延伸。濕式蝕刻可（例 如）包含在任-合適的濕式触刻溶液（例如1刺溶液或 刪溶液）中之㈣刻溶液可視基板而定。作為對雷 射切除之替代，例如，可使用乾式蝕刻（例如麵 反應性離子钮刻）或選擇性敍刻介電層的糊狀物之印 刷。 1 該複數個凹槽可（例如）&> μ l j如）為千订凹槽，例如，在與基 板表面平行之平面中具有矩形形狀。 凹槽之深度（亦即，在與基板表面正交之方向上的大 小）可（例如）在約 向大小（在與基板表面平行之方向上）可（例如）在約4〇 微米與2_之間的範圍中，例如，在約】⑼微米與imm ,間的範圍中’例如’大約谓微米。凹槽之間的間距可 (例如）在約60微米與3 _之間的範圍中。 在-具體實例中’凹槽在複數個凹 雜層下方在側向方向上延伸。換言之，在複數個凹=之= 一摻雜層（及上覆該第-換雜層之介電層）包含— 懸垂部分或一懸臂。此懸垂部分之側向大小可（例如）在 8 201203594 約1微米與5微米之間的範圍中。 步驟==步驟可包含以高各向異性執行離子植人 艾鄉電4播雜步驟或合適的低壓十植入 於大氣壓的壓力下）。各向異 ；;在低 :當在每-空間方向上考慮時該值相同=== *上下文中尤其關注的是與濃度有關之參數。月’ 在—具體實例中，該方法 散步驟前在該Λ柘夕步匕a在該摻雜劑擴 啊引隹及基板之一刖側處提供一第二 ^ 換雜層具有與該基板相同之摻雜 二：’㈣二 驟接著亦導致在石夕基板之前側處 ㈣雜劑擴散步 光伏打電池中提供前側場。 …區域’例如，在 ::具體實例中，該方法可進一步包含 =及在該後側處提供-表面純化層，在該前側處提供一 反射塗層及在該後側處提供發射極接點及基極接點。 k供發射極接點及基極接點可（例如）包含提供穿過 在於後側處之不同層的開口（例如，藉由雷射切除）， :局部曝露第一類型之穆雜區域及第二類型之摻雜區域。 “下來’可提供一薄金屬晶種層，接著為電鍍。或者，可 =由真空蒸鑛提供發射極接點及基極接點，其中懸臂之存 在可導致兩個接點類型之分離。 根據本發明之具體實例的製造方法之一優勢為其不使 用破影、。根據本發明之具體實例的方法可基於雷射圖案化 (其為清潔技術），底银及離子植入。 201203594 為了說月之目的，上文已描述本發明之某些目標及優 勢田然應理解，根據本發明之任一特定具體實例，未 必可達成所有此等目標或優勢。因此，舉例而言，熟習此 項技術者應認識到，可按達成或最佳化如本文中教示之一 優勢或優勢群組之方式體現或進行本發明，而未必達成可 如本文中教示或建議之其他目標或優勢…卜，應理解， 此發月内谷僅為一實例，且並不意欲限制本發明之範疇。 藉由參照當結合隨附圊式閱讀之以下詳細描述，可最好地 理解本發明（關於組織及操作方法連同其特徵及優勢 【實施方式】 在以下t羊細描述中，闡明眾多特定㈣，以便提供對 本發明及可在特定具體實财實踐其之方式的透徹理解。 然而’應理解’可在無此等特定細節之情況下實踐本發明。 在其他情況下’未詳細描述熟知方法、程序及技術，以便 不使本發明晦《懂。雖然將關於特定具體㈣且參看某 些圖式描述本發明’但本發明不限於此。…包括及描 述之圖式為示意性@，且不限制本發明之範疇。亦注意， 在圖式中，一些元件之大小可能被誇示，且因此，為了說 明性目的，未按比例繪製。 —此外，在描述中及在申請專利範圍中之術語第―、第 -、第三及類似者用於在類似元件之間區分，且未必用於 以時間方式、α空間方式、按等級或按任_其他方式描述 序列。應理解，在適當情況下，％此使用之術語可互換， 且本文中描述的本發明之具體實例能夠按與本文中描述或 10 201203594 說明不同之序列操作。 此外，在描述中及在φ 士主直而丨# m 在申D月專利乾圍中之術語頂部、底 邵、在....... V 、+ ^ ·. · ’.下及類似者係用於描述性目的， 且未必用於描述相對位置。 μ 置應理解，在適當情況下，如此 使用之術語可互換，日士 此 .A 、 本文中描述的本發明之具體實例能 句按與本文中描述或說明者不同之定向操作。 應注意到，術語「包含（comprising)」不應 限於其後列出之構件.農尤M咚甘a 釋马 、 m ^稱件，其不排除其他元件或步驟。其因此 應被解釋為指定如所转^私丨&杰、+、 怦心疋如所k到的陳述之特徵、整數、步驟或組 件之存在，但不排除—或多個其他特徵、整數、步驟或組In "Super self-aligned technology for backside contact solar cells: a route to low cost and high efficiency" (IEEE PVSC 2009), P. Verlinden et al. propose a method for manufacturing a back contact photovoltaic cell, which method Only one photolithography step is required, 4 201203594 The n+ doped region and the p + doped region at the back side of the cell are chemically etched in the germanium substrate by using an oxide mask and the bottom is covered. The cover is obtained by forming an oxide cantilever on the side of the groove. The bottom and sidewalls of the recess are thermally oxidized to provide a passivation layer and a nitride. The product is $, above the oxide layer. Next, an anisotropic reactive ion remnant is used, and the etched field is used as a mask, which is opened in the oxygen :: and vapor layer at the bottom of the groove. Oxygen cut layer and cut layer 2: Medium:: at the side wall. Subsequent to the butterfly pre-deposition, and in the single-high temperature step: two scattered regions (n + emitter region and two of the base are expanded to provide separation between the n + doped region and the p + doped region, Second: the oxygen cut/nitrogen cut stack at the sidewall of the trench is used as the shielding layer. For the emitter junction and the base junction, the A1 layer is deposited by a vacuum evaporation clock (the result: the heart is covered with a very poor step Characteristic), such that the existence of the cantilever leads to the separation between the cathode emitter contact and the base contact. [Invention] The specific example of the present invention has two types of tongs ^ φ ^ for the species A good method for manufacturing a battery that is too dangerous in the post-planting point. The above object is achieved by a specific example according to the present invention: =: method for photovoltaic cell burning, wherein the pairing is avoided The need for a quasi-step of the back-contact, and the need for the more previous steps and the number of counter-steps. In the basis of the specific example, the process is used to separate the "type doping region and the type: The side of the groove that is engraved in the stone substrate: or the shielding layer The J-edge cantilever or overhang portion is combined with the 201203594 directional doping for separation between the n-type doped region and the p-type doped region. The emitter and back surface can be formed in a single-step process. Diffusion of dopants in the field and front surface field. In addition, the cantilever can also be used for the split 35 between the emitter and base contacts, so that a single metallization step can form two contact types. In a specific example, the present invention relates to a method for fabricating an interdigitated back contact photovoltaic cell, the method comprising: on a rear surface of a semiconductor (eg, '矽') substrate a first doped layer of a first dopant type; providing a dielectric shielding layer overlying the first doped layer; forming a plurality of layers through the dielectric shielding layer and the first % music layer a groove 'the plurality of grooves extending in the direction of one of the rear surface of the rear-faced member (for example, orthogonal) to the stone eve and in the 丨 and the number of the grooves Extending ^ τ in the lateral direction below the first impurity layer, in the rear table In the direction of one of the positive fathers (eg, orthogonal), the L ^ vanadium-doping step is performed, whereby a first dopant type is provided at the bottom of one of the plurality of grooves a dopant of the type II dopant; a 勃-dopant diffusion step, thereby forming a type: doping between the plurality of grooves at the rear side of the far substrate a region and a doped region of the first type at the bottom of the plurality of grooves. Above the present invention @ . ^ ^ Hereinafter, "orthogonal with the back surface" is considered to be from the rear surface The orthogonality is not more than 10. The deviation of Θ is not more than 3. The preferred one of the specific examples of the present invention is . ^ _ , .s ΛΙ 类型 类型 盥 盥 盥 盥 盥 盥 盥 盥 盥Self-aligned, ^ ^ m P , does not need to provide a dedicated 6 201203594 mask or masking layer for separating the doped regions of the first type from the second type of doped regions. The specific example of this is that the advantage is that the emitter is generated at the same time. This provides a simplified way of handling solar cells. Surface field and in the specific example of the present invention, the substrate may be (for example, the first dopant type may be n-type, a # and n-type substrate 'in this specific example, the dopant-increasing dopant type may be ... an n-type region between the trenches (for example, a germanium-type region (for example, an emitter region) formed at the bottom of the plurality of recesses. The recessed or 'in the present invention has a switch-type substrate' first The dopant type may be, for example, · η is " In this specific example, 'the dopant diffusion step; - the p-type region between the trenches (for example, the emitter region) and the complex or in this Specific to the invention = area field). The type of substrate - dopant type can be, for example, ρ is n-type. In this specific example 1, the second (four) agent type may be a plurality of grooves between the grooves (four) steps may be formed in a plurality of metaphors ... and or in the specific real & emitter region of the present invention. The type of substrate, the first dopant type may be 'the substrate may be, for example, P is p-type. In this specific example, the #^=two dopant type may be an n-type Ba domain between the plurality of grooves: the dopant diffusion step may include forming at the bottom of the plurality of grooves... the emitter region) and the complex : p-type regions at two locations (eg, back surface field regions). The layer may, for example, be a mudo oxide layer or (iv) an amorphous half 201203594 conductor layer (e.g., an amorphous germanium layer). The dielectric shielding layer can be a single layer or a stack of layers. The dielectric masking layer can comprise any suitable dielectric layer, such as an oxide layer and/or a nitride layer. Forming the plurality of recesses can be performed, for example, by f-radiation (four) for a wet-type residual of the bottom-contact dielectric shielding layer and the first-wet layer, and the wet-touching step causes the recess to be doped in the first doping The extension of the layer below in the lateral direction (= 'peripherally parallel to the direction of the back surface'). Wet etching can, for example, be included in any suitable wet etch solution (e.g., a thorn solution or a dicing solution) depending on the substrate. As an alternative to laser ablation, for example, dry etching (e.g., surface reactive ion button etching) or a paste of a paste of a dielectric layer can be selectively used. 1 The plurality of grooves may be, for example, &> μ l j such as a thousand-doped groove, for example, having a rectangular shape in a plane parallel to the surface of the substrate. The depth of the groove (i.e., the size in a direction orthogonal to the surface of the substrate) can be, for example, at an approximate size (in a direction parallel to the surface of the substrate), for example, at about 4 Å and 2 _ In the range between, for example, in the range between about (9) micrometers and imm, 'for example, 'about micron. The spacing between the grooves can be, for example, in the range between about 60 microns and 3 _. In a specific example, the recess extends in a lateral direction below the plurality of recessed layers. In other words, a plurality of recesses = a doped layer (and a dielectric layer overlying the first alternating layer) comprise a depending portion or a cantilever. The lateral extent of the overhang portion can be, for example, in the range between about 8 microns and 5 microns at 8 201203594. The step == step may comprise performing an ion implantation with high anisotropy or a suitable low pressure of 10 implanted at atmospheric pressure. Differentiated;; at low: the same value when considered in the per-space direction === * The context is particularly concerned with the concentration-related parameters. In a specific example, the method provides a second replacement layer at the side of the dopant and a side of the substrate at the side of the substrate before the step of dispersing Doping two: '(4) The second step then leads to the provision of a front side field in the photovoltaic front cell at the front side of the Shixi substrate. ... region 'For example, in the:: specific example, the method may further comprise = and providing a surface purification layer at the back side, providing a reflective coating at the front side and providing an emitter contact at the back side And the base contact. The k-to-emitter junction and the base contact may, for example, comprise openings that provide passage through different layers at the back side (eg, by laser ablation): partial exposure of the first type of impurity region and Two types of doped regions. "Lower" can provide a thin metal seed layer, followed by electroplating. Alternatively, the emitter junction and the base junction can be provided by vacuum distillation, where the presence of the cantilever can result in the separation of the two junction types. One of the advantages of the manufacturing method of the specific example of the present invention is that it does not use imageing. The method according to a specific example of the present invention can be based on laser patterning (which is a cleaning technique), bottom silver and ion implantation. 201203594 The purpose of the present invention has been described above with respect to certain objects and advantages of the present invention. It should be understood that, in accordance with any particular embodiment of the present invention, all such objectives or advantages may not be achieved. The skilled artisan will appreciate that the present invention may be embodied or carried out in a manner that achieves or optimizes one of the advantages or advantages of the teachings herein, and does not necessarily achieve other objectives or advantages as may be appreciated or suggested herein. It should be understood that the valleys in this month are only an example, and are not intended to limit the scope of the present invention. By referring to the following detailed description in conjunction with the accompanying reading, the best geography is preferred. The present invention (with respect to the organization and method of operation, together with its features and advantages). In the following description, numerous specifics are set forth in order to provide a thorough understanding of the invention and the manner in which it can be practiced in a specific specific financial practice. The invention may be practiced without any of the specific details. In other instances, well-known methods, procedures, and techniques are not described in detail so as not to obscure the invention. The drawings illustrate the invention 'but the invention is not limited thereto. The drawings included and described are schematic @ and do not limit the scope of the invention. It is also noted that in the drawings, some elements may be exaggerated in size. And, therefore, for the purpose of illustration, the invention is not intended to Used to describe the sequence in a time mode, in an alpha space manner, in a grade, or in any other way. It should be understood that the terms used herein are interchangeable where appropriate. And the specific examples of the invention described herein can be operated in a sequence different from that described herein or illustrated in 10 201203594. In addition, in the description and in the terms of the φ 士 主 主 丨 m m m 申 申 申 申 申Top, bottom, and ... V, + ^ ·. · '. and similar are used for descriptive purposes and are not necessarily used to describe relative positions. μ should be understood, where appropriate The terms so used are interchangeable, and the specific examples of the invention described herein can be operated in a different orientation than that described or illustrated herein. It should be noted that the term "comprising" does not It shall be limited to the components listed below. Nong You M 咚 a a 、 、 m 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 The existence of a feature, integer, step or component of a statement as stated, but does not exclude—or multiple other features, integers, steps or groups
件或其群組之存在或添加。因此，表述「—裝置包含構件A 及B」之範疇不應限於裂置僅由組件八及B組成。 、=本發明之内容脈絡中，光伏打電池之前表面或前側 為適宜於朝向光源定向且因此適宜於接收照明之表面或 側。光伏打電池之背表面、背側、後表面或後側為與前表 面相反之表面或側。基板之前側為基板之對應於待製造的 光伏打電池之前側的側，而基板之後側或背側對應於待製 造的光伏打電池之背側。 在本發明之内容脈絡中，交指式意謂交纏式，藉此來 自:群組之項與來自另一群組之項交替呈現。詳言之，交 牦ίτ.關；ί?、光伏打電池之背接點。此交指式背接點之優勢為 無柵格遮光損失。 … 根據本發明之一具體實例的用於製造交指式背接點光 伏打電池之方法包含：在一半導體（例如，矽）基板之— 201203594 後表面上供"a] _ 唆 tΙΑ. . 第一摻雜劑類型之第一摻雜層；提 蔽二—推雜層之介電遮蔽層；形成穿過該介電遮 二：第一捧雜層之複數個凹槽，該複數個凹槽在與該 導體基板之該後表面實質上正交（例如，正交）之—方 =延伸至料導體基板内且在該複數個凹槽之側面在該 -摻雜層下方在一側向方向上延伸；在與該後表面實質 上：父之一方向上執行一定向摻雜步驟，藉此在該複數個 凹槽之一底部提供具有與該第一換雜劑類型不同的一第二 摻雜劑類型之播雜劑之換雜區域；執行—摻雜劑擴散步 驟，糟此在該基板之該後側處形成處於該複數個凹槽之間 的一第一類型之摻雜區域及在該複數個凹槽之該底部處的 一第一類型之摻雜區域。 根據根據-具體實例之方法的IBC光伏打電池之製造 製程之-實例說明於圖i至圖8中。針對一例示性具體實 例說明該方法，JL中佶用白人货 ,A A, ” T使用包3第一摻雜劑類型之摻雜劑的 半導體基板，例如’ η型石夕基板。半導體基板1〇之摻雜濃 度可（例如）使得基板之電阻率處於約〇 5 〇hm_Cm盥⑴ 0hm-cm之間的範圍中 '然而，該方法不限於此，且亦可用 於在另-半導體材料之基板（例如，鍺基板）及/或另一推 雜劑類型之基板（例如’ P型基板）及/或其他摻雜劑漢度 (因此，其他電阻率）之基板上製造光伏打電池。 在紋理化了 η型基板10之前側後，在基板之後側處提 供包含第-類型之摻雜劑（例如，η型摻雜劑）的第一摻雜 層（例如，第-氧化物層U)，諸如，推雜麟之氧化物層。 12 201203594 第一摻雜層11之厚度可處於約2 圍[在本發明之具體實例中，第：二00-之間的範 度可處於】⑽一與5e20/cm3第一t雜層11之換雜劑濃 之前側處提供包含第—類之間的叙圍令。可在基板 的第二摻雜層（例二：::劑(例如，η型摻雜劑) 雜鱗之氧化物層。第上氧化物層12)，諸如，穆 __之門^ 雜層12之厚度可處於約與 ζυυ nm之間的範圍中。太 ^ 圍中。第-及第二摻雜層一 ⑴可（例如）為P0C13 ^雜鱗之氧化物層11、 習此項技術者已知之任|》雜奴CVD氧化物或熟 推雜氧化物層u及第二他：適的換雜氧化物 例如，在-個氧化步料。^化=#12可被同時提供， 可使嶋此項一之:: = =、 如，離子植入矽層。 u^•之掺雜層，诸 接下來’如在圖2中 介電層或-介電層堆疊13，該介電層;= : = ' 雜層，例如，氧化物層u。 1上覆5亥第一摻 -沈積之氧化砂層（例如，：有電=13可(例二包含 的範圍中之厚度）及/或氮化 例1 u米之間 與则謂之間的範圍中之厚/例如，具有在、約50謂 ⑼麵之間的範圍中之厚；^例如，具有在約50⑽與 在後側處之介電層=，Γ，具有約100nm之厚度）。 如，氮化石夕層），其可用：二包含用於純化之材料（例 /、 虱源來鈍化光伏打電池之後表 13 201203594 面。此外，其可提供保護以免受在製程之形成電極的稍後 階段中所提供之金屬的影響。在本發明之其他具體實例 中’可在製程之稍後階段中提供一後表面鈍化層或層堆 叠，在此等具體實例中，在執行了播雜劑擴散步驟後可移 除存在於基板之後側處的所有層（第一摻雜層n，及若存 在）ι電層堆疊1 3 )，且然後可提供一後側鈍化層或層堆 疊。 在前側處’可在第二換雜氧化物層12上提供諸如氮化 石夕層14之額外層。氣化石夕層14可充當最終光伏打電池,士 構中W塗層。因此’氮切層14之厚度較佳地處: 約5〇 _與150⑽之間的範圍中。然而，在本發…他 具體實例中，可在製程之稍後階段中（❹，在執行換 雜劑擴散步驟後）提供一抗反射塗層。在此等具體實例中： 可移除第二摻雜層12，且可在勃耔 仃了摻雜劑擴散步驟後且 在k供抗反射塗層前提供一表面鈍化層。 在接下來的步驟中，在基板1〇之後側的在製程 ==發射極區域之位置處將複數個凹槽17形成於 基板材枓（例如，矽（圖3 ))中。 除报&…机， 了（例如）藉由雷射切 4成讀個凹槽17。凹槽17具有對應於將在 階段中形Μ㈣㈣賴後 ^ 狀舉例而言，凹# :在根據平行於基板後表面之平面的橫截面中具有實心 矩形形狀（例如，矩形形狀），從 ' 電池之長度，且具有（例如）在約4〇微^=成的光伏打 r阴a / U水與2 mm之間的 (例如)在約1〇0微求與〜之間的範圍中、（例 201203594 如）大約300微米的寬度W。凹槽之間的間距？可（例如） 處於約60微米與…之間的範圍中。凹槽之深度大於將 在製程之稍後階段中形成的背表面場之深度。凹彳f < &、终 深度d (圖4中所示，凹槽17在基板材料内之實:深度 可（例如）處於約500 nm與10微米之間（例如，處於約^ 微米與5微米之間）的範圍中。作為對用於形成凹槽η的 雷射切除之替代’可使用熟習此項技術者已知之9其他方 法，諸如，微影及DRIE蝕刻或絲網印刷用於蝕刻介電層之 蝕刻糊狀物，接著為在基板材料（例如，矽）中蝕刻二=。 在雷射切除後，執行濕式化學蝕刻，例如，藉由基於 NaOH或基於K0H的㈣溶液，使用介電層13作為二蔽 層。基於NaOH (或KOH)㈣刻溶液可（例如）包含每t 公升AO約l00g至2〇〇gNa〇H(或K〇H)，且可在約以 °C或更小之溫度下執行_。然巾，在根據—具體實例之 方法中，可使用熟習此項技術者已知之其他合適的蝕刻溶 液，諸如，基於ΗΝ03+卿瑪〇的钮刻溶液。蚀刻溶液經 選擇、’使得基板材料具有比在後側處之上覆層π、13快的 I虫刻速率。濕式化學㈣步驟藉由雷射切除步驟移除可能 在基板材料（例如，石夕）中造成之㈣，且歸因於與介電 層13及第一摻雜層（例如’氧化物層"）之蝕刻速率 快的基板（例如1 土板10 )蝕刻速率而產生底省虫。此導 =圖4中所示之結構。歸因於底敍，在凹槽π之側面， =摻雜層（例如，氧化物層1υ及介電層13形成懸垂. 口刀’懸臂。懸垂部分之寬度w。或因此底蝕之深度可（例 15 201203594 如）處於約1微米與5微米之間的範圍中。 在圖5中說明之接下來步驟中， 質上正交（例如，正交）之方向：/與後表面之平面實 藉由第二類型之摻雜劑(例如:ρ:::… 驟，諸如，硼植入步驟。作為：:：雜劑）之定向摻雜步 之扯果，勺人哲 作為摻雜步驟（例如，植入步驟） 之摻雜劑(例如，。"播雜劑，諸如， 之底部二 形成於基板10之後側處複數個凹槽17 =步:射極區域將形成於該底部。由於植入為高度定 在凹样之底邻：在凹槽17之側面的懸臂之存在猶後導致將 發射使用穆雜區域18作為推雜劑源）的 層11作心、將在凹槽17之間形成（使用第一摻雜氧化物 在本發明 源)的背表面場(BSF)區域之間的分離。 =明：具體實例中，可使用與離子植入不同的定向摻 如’電㈣雜或為熟習此項技術者已知之任一 ”他疋向換雜步驟。 ^來，（例如）在約5至1〇分鐘期間在約着c斑 一單：間的範圍中之溫度下執行高溫步驟，從而導致(： :/至=)第二類型換雜劑（例如，硼）自穆雜區域 矽） ’板10之後側處之凹槽中的基板材料（例如， 形:發射極區域20;導致第一類型播雜劑(例 板表J >雜層（例如，氧化物層Η)擴散至在基 表面之後側在凹槽17之間的基板材料（例如，们内， 错此形成背表面場區域2丨. 碟)自第二摻雜層：，：==_雜軸 在别側處之氧化物層I 2 )之擴 16 201203594 散，藉此在光伏打電池之 ^ 區域22。歸因於在凹槽17化之則表面處形成前表面場 缺# 他 3 之側面的懸臂之存在，此製% 致第一摻雜劑類型之區 表秩導The presence or addition of a piece or group thereof. Therefore, the expression "--devices include components A and B" should not be limited to the splitting consisting only of components eight and B. In the context of the present invention, the front surface or front side of the photovoltaic cell is a surface or side that is adapted to be oriented towards the light source and is therefore suitable for receiving illumination. The back surface, back side, back surface or back side of the photovoltaic cell is the opposite surface or side to the front surface. The front side of the substrate is the side of the substrate corresponding to the front side of the photovoltaic cell to be fabricated, and the back side or back side of the substrate corresponds to the back side of the photovoltaic cell to be fabricated. In the context of the present invention, interdigitated means entangled, whereby items from a group are alternately presented with items from another group. In detail, pay 牦 ίτ. off; ί?, photovoltaic battery back contact. The advantage of this interdigitated back contact is the loss of no grid shading. A method for fabricating an interdigitated back contact photovoltaic cell according to an embodiment of the present invention comprises: "on a surface of a semiconductor (eg, germanium) substrate - 201203594, "a] _ 唆tΙΑ. a first doped layer of a first dopant type; a dielectric shielding layer of the second doping layer; a plurality of recesses formed through the dielectric mask: the first doped layer, the plurality of recesses The trench is substantially orthogonal (eg, orthogonal) to the back surface of the conductor substrate - extending into the material conductor substrate and on the side of the plurality of recesses under the doped layer on one side Extending in a direction; performing a certain doping step in a direction substantially from the back surface: one of the fathers, thereby providing a second doping at the bottom of one of the plurality of grooves having a different type from the first dopant a dopant-doping region of the dopant type; performing a dopant diffusion step, forming a first type of doped region between the plurality of recesses at the back side of the substrate and a first type of doped region at the bottom of the plurality of recessesAn example of the manufacturing process of an IBC photovoltaic cell according to the method of the specific example is illustrated in Figures i to 8. The method is described for an exemplary specific example, in JL, a white metal, AA, "T" semiconductor substrate using a dopant of the first dopant type of package 3, such as a 'n-type shixi substrate. a semiconductor substrate 1 〇 The doping concentration may, for example, cause the resistivity of the substrate to be in a range between about 〇5 〇hm_cm 盥(1) 0 hm-cm. However, the method is not limited thereto, and may also be applied to a substrate of another semiconductor material ( For example, a germanium substrate) and/or another dopant type substrate (eg, a 'P-type substrate) and/or other dopants (and thus other resistivity) substrates are fabricated on a photovoltaic cell. After the front side of the n-type substrate 10, a first doped layer (eg, a first-oxide layer U) including a dopant of a first type (eg, an n-type dopant) is provided at a rear side of the substrate, such as 12, 201203594 The thickness of the first doped layer 11 may be about 2 [in the specific example of the present invention, the range between the two: 20- may be in the (10) one and 5e20 /cm3 of the first t-heterogeneous layer 11 is provided at the front side of the thicker The second doping layer can be in the second doped layer of the substrate (Example 2:::agent (for example, n-type dopant) oxide layer of the impurity scale. The upper oxide layer 12), such as, The thickness of the impurity layer 12 may be in a range between about ζυυ nm and ζυυ nm. The first and second doped layers (1) may, for example, be P0C13 ^ oxide layer 11 of the scale Anyone known to the skilled person of the art | "Small NP oxide or cooked push oxide layer u and second: suitable replacement oxide, for example, in - oxidation step. ^化=#12 Provided at the same time, it is possible to make this one:: = =, for example, ion implantation into the germanium layer. The doping layer of u^•, the next 'as in Fig. 2 dielectric layer or - dielectric layer stack 13 , the dielectric layer; = : = ' impurity layer, for example, oxide layer u. 1 overlying 5 hai first doped-deposited oxidized sand layer (for example, there is electricity = 13 may be included in the range of Thickness) and/or nitridation in the range between 1 u m and then is thick, for example, having a thickness in the range between about 50 and (9) faces; for example, having a relationship of about 50 (10) and Dielectric layer at the back side =, Γ, with A thickness of about 100 nm. For example, a nitride layer), it can be used: two materials for purification (example /, 虱 source to passivate the photovoltaic cell after the surface of Table 13 201203594. In addition, it can provide protection from The process forms the effect of the metal provided in a later stage of the electrode. In other embodiments of the invention, a back surface passivation layer or layer stack may be provided in a later stage of the process, in such specific examples, All of the layers (first doped layer n, and if present) present at the back side of the substrate may be removed after the dopant diffusion step is performed, and then a backside passivation layer may be provided Or layer stacking. An additional layer such as a nitride layer 14 may be provided on the second alternate oxide layer 12 at the front side. The gasification layer 14 can serve as the final photovoltaic cell, the W coating in the structure. Thus, the thickness of the nitrogen cut layer 14 is preferably in the range between about 5 〇 _ and 150 (10). However, in the present invention, in his specific example, an anti-reflective coating may be provided in a later stage of the process (❹, after performing the dopant diffusion step). In these specific examples: the second doped layer 12 can be removed and a surface passivation layer can be provided after the porphyrin dopant diffusion step and before the k antireflective coating. In the next step, a plurality of grooves 17 are formed in the substrate sheet 枓 (e.g., 矽 (Fig. 3)) at the position of the process == emitter region on the rear side of the substrate 1?. In addition to the &... machine, a groove 17 is read, for example, by laser cutting. The groove 17 has a shape corresponding to a shape which will be in the stage (4) and (4), and has a solid rectangular shape (for example, a rectangular shape) in a cross section according to a plane parallel to the rear surface of the substrate, from the 'battery The length, and having, for example, a range between about 4 〇 ^ 的 光伏 光伏 a a a a / U water and 2 mm (for example) between about 1 〇 0 micro and 〜 Example 201203594 such as a width W of approximately 300 microns. The spacing between the grooves? It can, for example, be in the range between about 60 microns and about. The depth of the groove is greater than the depth of the back surface field that will be formed in a later stage of the process. Concave f <&, final depth d (shown in Figure 4, the recess 17 is within the substrate material: the depth can be, for example, between about 500 nm and 10 microns (eg, at about ^ microns and In the range of between 5 micrometers. As an alternative to laser ablation for forming the groove η, other methods known to those skilled in the art, such as lithography and DRIE etching or screen printing, can be used. Etching the etch paste of the dielectric layer, followed by etching two in the substrate material (eg, germanium). After laser ablation, performing a wet chemical etch, for example, by NaOH based or K0H based (iv) solution, The dielectric layer 13 is used as a two-layer layer. The NaOH (or KOH) based solution may, for example, comprise from about 100 g to 2 〇〇g Na 〇 H (or K 〇 H) per t liter of AO, and may be in about At a temperature of C or less, in the method according to the specific example, other suitable etching solutions known to those skilled in the art, such as a button engraving solution based on ΗΝ03+卿玛〇, may be used. The solution is selected, 'so that the substrate material has a coating π, 1 above the back side 3 fast I insect rate. Wet chemical (4) step by laser removal step removal may be caused in the substrate material (eg, Shi Xi) (four), and due to the dielectric layer 13 and the first doping The etch rate of the substrate (eg, 1 slab 10) with a fast etch rate of the layer (eg, 'oxide layer') produces a bottom worm. This is the structure shown in Figure 4. Due to the bottom, in the concave The side of the groove π, = doped layer (for example, the oxide layer 1 and the dielectric layer 13 form a dangling. The knife's cantilever. The width of the overhanging portion w. or thus the depth of the undercut can be (Example 15 201203594) In the range between 1 micrometer and 5 micrometers. In the next step illustrated in Figure 5, the direction of the mass orthogonal (e.g., orthogonal): / the plane with the back surface is actually doped by the second type Agent (for example: ρ:::, such as, boron implantation step. As::: miscellaneous agent), the orientation of the doping step, the scoop of the person as a doping step (for example, the implantation step) A dopant (for example, a "proppant, such as the bottom two is formed at the back side of the substrate 10 at a plurality of grooves 17 = step: The pole region will be formed at the bottom. Since the implant is highly positioned at the bottom of the concave sample: the presence of the cantilever on the side of the groove 17 will eventually cause the layer 11 to emit the use of the impurity region 18 as the source of the dopant. Separation between the back surface field (BSF) regions that will be formed between the grooves 17 (using the first doped oxide at the source of the invention). = Ming: In a specific example, ion implantation can be used Different orientations are incorporated as 'electric (tetra) or any one known to those skilled in the art." He comes, for example, at about 5 to 1 minute during a period of about c: The high temperature step is performed at a temperature in the range of between, resulting in (:: to to =) the second type of dopant (for example, boron) from the impurity region 矽) the substrate material in the groove at the rear side of the board 10 (eg, shape: emitter region 20; resulting in a first type of dopant (eg, a plate J > a hetero layer (eg, an oxide layer) diffuses to the substrate material between the grooves 17 on the back side of the base surface) (For example, in this case, the back surface field area is 2 丨. disc) from the second doped layer:,:==_ Side of the oxide layer I 2) of the spread dispersion 16201203594, whereby the play in the photovoltaic cell 22 ^ region. Due to the presence of the cantilever on the side of the front surface field at the surface where the groove 17 is formed, the % guide to the first dopant type is derived.
Jty- ^ 〔例如，n+區域（BSF區域21)、 ”在後側處的I㈣劑類 & )) 射極區域2〇))之分離，而，域（例如，p+區域（發 ω ^ , 而不需要提供遮蔽層，例如，在 凹槽之側壁處。所得結構展示於圖6中。 在 =來’在結構之後側處’更詳言之，在凹槽 珞之基板表面（例如，矽矣 < 曝 7 s 表面）處提供一表面鈍化層23(圖 且匕 化層23可（例如）為包含熱氧化物（例如， :…、約3 -與1〇峨之間的範圍中之厚度）及沈積之氧 化物或氣化物之—堆& 隹且或包含αι2〇3層（例如，具有大約 之厚度）及沈積之氧化物層或氮化物層或任一盆他層 ，一堆疊或適合於鈍化且為熟習此項技術者已知之層之： 登。 在本發明之替代具體實例（圖式中未說明）中，可在 2雜劑擴散步驟後移除先前提供於基板10上之不同層（介 $層13、第—摻雜層11、第二摻雜層12)，接著為在基板 之整=(及前）表面之上提供-表面鈍化層。 "另衣私步驟包含形成穿過在後側處之層直至經摻雜 ，半導祖基板材料（例如，矽）#開口（例如，藉由雷射 更刀除）以允許形成至發射極區域2〇及bsf區域21的金屬 衣成穿過表面鈍化層23之開口，使得局部曝露發 射極區域20。亦提供穿過凹槽丨7之間的層（在展示之實例 中，第一摻雜氧化物層u、介電層13)之堆疊之開口，使 17 201203594 得在說明之具體實例中，局部曝露n +摻雜BSF區域2 1。 最後’穿過開口（其穿過覆蓋半導體（例如，碎）基 板10之後側的層而形成）提供金屬接點，更詳言之，至發 射極區域20之發射極接點24及至BSF區域2 1之基極接點 2 5 (圖8 )。發射極接點2 4與基極接點2 5較佳地為交指式， 且可（例如）為梳狀。可在單一製程中進行用於形成兩個 接點類型之金屬化。由於凹槽17之存在，因此可獲得發射 極接點24與基極接點25之間的電極分離，從而導致在凹 槽之邊緣處的金屬不連續《舉例而言，藉由晶種層（例如， 包含Ti/Cu堆疊的約100 nm厚的晶種層）之沈積 '接著為 電鍍（例如，約4微米厚的Cu電鍍），或藉由金屬層（例 如，約1微米厚A1層）之沈積，可進行金屬化。 雖然圖1至圖8說明其中發射極區域形成於複數個凹 槽之底部處且B S F區域形成於凹槽之間的製程序列’但本 發明不限於此。舉例而言，亦可使用用於製造其中BSf區 域形成於凹槽之底部處且其中發射極區域形成於凹槽之間 的IBC電池之方法。 前述描述詳述了本發明之某些具體實例。然而，應瞭 解不管前述内容在文字方面顯得有多詳細，均可以許多 方式實踐本發明。應注意，當描述本發明之某些特徵或態 樣時的特定術語之使用不應被認為暗示該術語在本文中被 重新定義以限於包括彼術語相關聯的本發明之特徵或態樣 之任何特定特性。 雖然以上詳細描述已展示、描述及指出如適用於各種 18 201203594 :、脰Λ例的本發明之新穎特徵，但應理解，在不脫離本發 月之精神的情況下，熟習此項技術者可進行 或和^ | °凡％的裝詈 之形式及細節之各種省略、取代及改變。 夏 【圖式簡單說明】 圖1至圖8示意性說明根據本發明之一具體 例+ a a W之― J不性方法。 在不同圖式中，相同參考記號指相同或相似元件。 【主要元件符號說明】Jty-^ [eg, n+ region (BSF region 21), "I(four) agent class at the back side &))) The separation of the emitter region 2〇)), while the domain (for example, p+ region (transmits ω ^ , There is no need to provide a masking layer, for example, at the sidewall of the groove. The resulting structure is shown in Figure 6. At the end of the structure, at the side of the structure, in more detail, the surface of the substrate on the groove (for example, 矽A surface passivation layer 23 is provided at the 矣 < exposure 7 s surface (Fig. and the annihilation layer 23 can, for example, be in the range of containing thermal oxides (e.g., ..., between about 3 and 1 〇峨) Thickness) and deposited oxide or vaporized -heap & or comprising a layer of alpha (for example, having a thickness) and a deposited oxide or nitride layer or any other layer, a stack Or suitable for passivation and layers known to those skilled in the art: In an alternative embodiment of the invention (not illustrated in the drawings), the previously provided substrate 10 can be removed after the 2 dopant diffusion step. Different layers (layer 13, layer - doped layer 11, second doped layer 12), followed by the substrate = (and The front surface is provided with a surface passivation layer. The additional step includes forming a layer through the back side until doped, semi-conductive substrate material (eg, germanium) # openings (eg, by Ray) The metal is allowed to pass through the opening of the surface passivation layer 23 such that the local exposed emitter region 20 is also provided through the recess 丨7. The opening of the stack of layers (in the example of the display, the first doped oxide layer u, the dielectric layer 13) is such that, in the specific example of the description, 201202594, the n + doped BSF region 2 1 is locally exposed. 'through the opening (which is formed through a layer covering the back side of the semiconductor (eg, shredded) substrate 10) provides a metal contact, more specifically, to the emitter contact 24 of the emitter region 20 and to the BSF region 2 1 The base contact 2 5 (Fig. 8). The emitter contact 24 and the base contact 2 5 are preferably interdigitated and can be, for example, comb-shaped. It can be used in a single process. Metallization of two contact types is formed. Due to the presence of the recess 17, an emitter can be obtained Electrode separation between point 24 and base contact 25 results in discontinuity of the metal at the edge of the groove. For example, by a seed layer (eg, about 100 nm thick comprising a Ti/Cu stack) The deposition of the seed layer is followed by electroplating (eg, about 4 microns thick Cu plating) or by deposition of a metal layer (eg, about 1 micron thick A1 layer). Although Figure 1 to Figure 8 illustrates a program column in which an emitter region is formed at a bottom of a plurality of grooves and a BSF region is formed between the grooves. However, the present invention is not limited thereto. For example, it may also be used to manufacture a BSf region formed therein. A method of forming an IBC cell at the bottom of the recess and in which the emitter region is formed between the recesses. The foregoing description details certain specific examples of the invention. However, it should be understood that the present invention can be practiced in many ways, no matter how detailed the text is. It should be noted that the use of specific terms when describing certain features or aspects of the invention should not be construed as implying that the terms are re-defined herein to be limited to any of the features or aspects of the invention that are included in the term. Specific characteristics. Although the above detailed description has shown, described and illustrated the novel features of the present invention as applicable to the various embodiments of the invention, it is understood that those skilled in the art may, without departing from the spirit of the present invention. Occur, replace, and change the form and details of the decoration of the %. [Simultaneous Description of the Drawings] Figs. 1 to 8 schematically illustrate a method of + a a W in accordance with an embodiment of the present invention. In the different figures, the same reference numerals refer to the same or similar elements. [Main component symbol description]
19 S19 S